Roosters singing egg song?

I noticed this today. SOmebody was singing the egg song REALLY LOUD and when I looked, it was rooster #2. A few hens were singing along. Then EVERYBODY got in on it, including rooster #1. After they got as loud as they could get, they all shut up.

My previous rooster would loudly in in othe egg song every time a hen was laying. Since he is now gone, I have a hen who took his place. She goes and sits with the rest of the ladies and sings for them. I guess she is just making the announcement for them since I do have a few who are very quiet and do not make much noise while laying.

I would be interested to see if there is another reason other than being quirky!